Transcript Document

Thermal and Moisture Protection
1
Major Topics


Moisture Control
Waterproofing
Membrane
 Clay
 Cementitious


Dampproofing
Hot-applied
 Cold-applied

2
Major Topics con’t

Building Insulation
Rigid
 Mineral Fiber
 Loose-fill
 Foamed-in-place


Roofing
Low vs. steep slope
 Types of roofing materials

3
Major Topics con’t



Flashing
Siding
Sealants
4
Moisture Control

Moisture is NOT damaging to construction in
its vapor form…the problems arise as it
Condenses (liquefies)
 Freezes (solidifies)


These may cause organic materials to
decay, metals to corrode, paint coatings to
blister, and in the case of freezing, may
cause concrete and masonry to crack.
5
Key Moisture Absorption Considerations




Dimensional instability – the changes in moisture
can cause a change in material dimensions (ex:
wood drying)
Deterioration – causes physical, chemical, and
biological breakdown of materials (ex: steel
rusting)
Condensation tolerance – varies for each
material
Effect on heat flow – if material contains moisture
it can increase the conductivity
6
Permeability




Permeance – measure of water vapor’s flow
through a material of specific thickness or an
assembly of several materials
Metals & glass – very low permeability
Materials with a permeance of 0-1 are
considered vapor retarders
See Figure 7.1-7 on page 431 for examples
of various materials and their permeance
7
Moisture Condensation

Moisture condensation in walls, floors, and
roof and ceiling assemblies can be controlled
by:
Providing a vapor retarder on the interior side
of the assembly which limits vapor entering
the structure
 Provide adequate ventilation for the structure
in spaces such as attic areas and crawl
spaces

8
Waterproofing
As defined in ASTM D1079: “the
treatment of a surface or a
structure to prevent the passage
of water under hydrostatic
pressure.”
9
Membrane

Fluid-applied membranes are
usually:
Polyurethane
 Hot Rubberized Asphalt – not as
elastic as polyurethane and
requires a thicker coat

10
Sheet Membranes





Butyl synthetic rubber sheet [60
mils thick]
Ethylene propylene diene
monomers (EPDM) [min. 1/16”
thick]
Pre-molded bituminous [7 ply]
Rubberized asphalt [56 mils]
Self-adhesive butyl [60 milsrequires adhesive primer]
11
Bituminous



Usually applied on vertical belowgrade surfaces
Hot coal-tar pitch or hot asphalt
The number of plies, overall
thickness, and content vary
according to the depth of the
hydrostatic head (in ft. – all
increase as the depth increases)
12
Clay waterproofing



Bentonite clay – when wet, it
expands to between 10 to 15 times
its dry volume.
It is typically mixed with water &
sprayed in place (also available in
dry sheets between cardboard)
Placed below grade to exterior
surfaces
13
Cementitious Waterproofing



Composed of portland cement,
aggregate, and an acrylic or plastic
admix.
It may also contain iron fillers (then
known as iron oxide waterproofing)
Hydraulic cement – another form
of cementitious waterproofing used
to seal holes, cracks and open
joints (often in free-flowing water)
14
Dampproofing



May be hot- or cold- applied
Hot consists of an asphalt primer
or a coal-tar-based primer
Used on the exterior of buildingsnot interior because of lingering
odor and the problems associated
with using “hot” products indoors.
15
Building Insulation


Usually added to the roof, walls,
and floors of a structure
4 basic classifications are:
Rigid board
 Mineral fiber
 Loose fill
 Foamed-in-place


Listed according to their R-Values
16
Rigid Insulation


Usable in all parts of a building –usually in a board form
Most are [Resistance/inch]:









Polystyrene – sensitive to daylight, give off carbon monoxide
while burning
Polyurethane [6.25] – may expand after exposure to moisture
Polyisocyanurate [7.2]
Perlite [2.78] – will not burn, tends to absorb water
Phenolic [8.3] –breaks easily, corrodes metal
Cellular glass block- [2.5] – breaks easily, deteriorates if
exposed to freezing & thawing
Organic fiber – roofing systems primary use, wood fibers and
water resistant binders
Glass fiber
Composites – take advantage of high R-values of some
materials in combination with the stability of others
17
Mineral Fiber Insulation



Products made from fibers from
rock, slag, or glass
Naturally resistant to fire, moisture,
and vermin
May be semi-rigid boards, batts, or
blankets (longer than batts and
sold in large rolls). Intended to fit
between studs (16” or 24” o.c.)
18
Loose-fill Insulation



Comprised of fibers, granules, or
chips
May be poured or “blown” into
attics or wall cavities
Common additives may include:
adhesives, and chemical
treatments to resist fire and vermin
19
Foamed-in-place Insulation



Created by a chemical reaction
that expands a mixture of
components as much as 30 times
Curing typically takes from 24-72
hours, at which time the mixture
solidifies into a cellular plastic
Care must be taken not to “overfill”
a cavity
20
Roofing



Low slope – in general, these are
roofs which slope less than
41/2”/ft.
On low slope roofs a system of
compatible components is selected
to work together to form a
waterproof membrane
Common systems used are: builtup roof or single-ply
21
Examples of Single-Ply
Membranes




EPDM – [ethylene propylene diene monomer] factory
cured elastomer, bonded to themselves using
adhesives
CSPE (DuPont Hypalon) –synthetic rubber, may also
be liquid
CPE – un-reinforced or polyester reinforced sheet
material
PIB – formulated from isobutylene and other
polymers, carbon black, and additional additives
22
Example of Built-up Roof
23
Steep Roofing



Slopes exceed 41/2”/ft.
Many materials used in modern
roofing practices existed centuries
ago (clay tiles, and stone)
Material used is based on: cost
criteria, slope of roof, expected
service life, wind resistance, fire
resistance, and local climate.
24
Roofing Material and Slope
Min.
Slope
2 in 12
Type of roof
3 in 12
Mineral fiber-cement shingles,
wood shakes or shingles
Slate shingles, concrete tile (other
than flat)
4 in 12
5 in 12
Asphalt shingles (warranty may
require a steeper slope - 4 in 12)
Flat clay tile, concrete tile
25
Roofing Underlayment


Should be asphalt-saturated felt
(usually a No. 15 or No. 30 used,
may require more than 1 layerdepending on roofing material
selected) –see pg 463, fig 7.6-6
Applied immediately after the roof
sheathing is in place
26
Underlayment Performs These
Functions:



Protects sheathing from moisture
absorption
Prevents the entrance of winddriven rain onto sheathing
Prevents direct contact between
asphalt shingles and resinous
areas in wood sheathing
(chemically incompatible-may
damage shingles)
27
Types of Roofing Materials






Asphalt shingles
Slate
Tile
Mineral-Fiber-Cement shingles
Wood shingles and shakes
Metal
28
Roofing Styles
29
Examples
30
Examples
31
Examples of Roofing
http://www.tricityroofing.com/types.html
32
Comparison of Types of Roofing
http://aihomeinspection.com/exterior.html
33
Flashing


Should be installed at all intersections of other roofs,
walls, and projections from roof.
Flashing should be made of corrosion resistant
materials such as:




Galvanized or stainless steel (min 26 gauge)
Aluminum (0.019 inch min.) –avoid using next to
masonry
Copper (16 oz.) –if not lead coated…may stain
surrounding materials
Flexible sheet- made of PVC or modified polymersused in single-ply & some BUR [built up roof]
34
Typical Locations for Flashing





Valleys –joint formed by 2 sloping
roofs
Chimney
Eaves – ice forming along the
eaves
Drip edge
All roof penetrations
35
Siding


The type of wall siding selected depends on
cost, expected life service, wind resistance, fire
resistance, local climate, and maintenance.
Possible materials include:
Mineral-Fiber-Cement shingles
 Wood shingles & shakes
 Aluminum and Vinyl siding
 Wood or Hardboard siding

 Bevel,
Tongue & Groove, Lap, Board and Batten
 (see pages 519-522 for examples of these)
36
Sealants

Basic types of building sealants include:
Elastomeric (rubber like) –polysulfides, silicone,
polyurethane [expansion joints]
 Solvent release curing [small-joints (3/16” or less]
 Latex emulsion [small interior joints, doors,windows]
 Tape [glazing, concealing lap joints]
 Acoustical [seal sound transmission, electrical
outlets]
 Preformed Foam
 Oil-based caulking compounds [doors, windows,
masonry subject to little or no movement]

37
References







Construction Materials and Processes, 3rd Edition. Watson, Don A..
McGraw-Hill, 1986. Imprint 2000. ISBN: 0-07-068476-6
Construction Principles, Materials, and Methods, Seventh Edition. H.
Leslie Simmons, John Wiley and Sons, Inc., 2001.
Olin’s Construction Principles, Materials, and Methods, Eighth Edition.
H. Leslie Simmons, John Wiley and Sons, Inc., 2007
Architectural Materials for Construction, Rosen, Harold J. and
Heineman, Tom. McGraw-Hill, 1996. ISBN: 0-07-053741-0
Basic Construction Materials, 6th Edition. Marotta, Theodore W.
Prentice Hall, 2002. ISBN: 0-13-089625-X
Building Construction: Materials and Types of Construction, 6th Edition,
Ellison, Donald C., Huntington, W.C., Mickadeit, Robert E.. John Wiley
& Sons. ISBN: 0-13-090952-1.
Architectural Graphic Standards: Student Edition, Abridgment of 9th
Edition. The American Institute of Architects. John Wiley & Sons.
ISBN: 0-471-34817-1
38